The gains come after U.S. stocks ended 2012 with their strongest rally in over a month, boosting the S&P 500 up 13.4 percent for the year, after a flat performance in 2011.

Late Tuesday, lawmakers passed legislation that prevented most impending tax increases and postponed spending cuts by two months, while raising taxes on the wealthiest 2 percent of Americans. (Read More:Rocky Path Ahead Even as Markets Cheer Fiscal Deal)

Global markets welcomed the news, with Asian and European markets rallying across the board.

President Barack Obama praised the bi-partisan deal but said there was more work to be done, saying it was "just one step in the broader effort to strengthen the economy."

While the vote averts immediate pain like tax hikes for almost all U.S. households, it does little to resolve other political showdowns on the budget that loom in coming months. Spending cuts of $109 billion in military and domestic programs will only be delayed for two months.

Zipcar surged about 50 percent on news that the car rental firm is being bought by Avis Budget Group for $12.25 per share in cash, or $500 million.

Bank of America also gained on a Wall Street Journal report that the company could be in position to repurchase the $5 billion stake that Warren Buffett took in 2011.

Apple jumped nearly 3 percent in pre-market trading amid reports the company has begun testing hardware for the iPhone 6. Meanwhile, Raymond James lowered its price target on the company to $690 from $700.

Facebook rallied after JPMorgan lifted its price target on the social-networking company to $35 from $29 and Cowen & Co. initiated coverage of the firm with a "neutral" rating.

On the economic front, the Institute for Supply Management's (ISM) non-manufacturing index, which tracks monthly changes in the services sector, is due out at 10 a.m. New York time on Wednesday. Economists polled by Reuters predict activity increased in December from 49.5 to 50.2. A reading above 50 indicates a sector expansion.

And construction spending data for November will also be released at 10 am. Economists polled by Reuters forecast spending rose by 0.8 percent in November against a 1.4 percent rise in October.